The Total War: Shogun 2 Limited Edition delivers instant access to exclusive and free content to both the single player and multiplayer modes of the game.

Total War: Shogun 2 Limited Edition Extra Content:

Exclusive ninja clan – the Hattori clan are masters of the Iga-ryu ninjutsu - a unique collection of martial skills and guerrilla techniques. This additional in-game faction is only available in the Limited Edition and includes the most powerful battlefield ninja units.
Extra historical scenario - The Battle of Nagashino saw an alliance between the Oda and Tokugawa clans clashing against the legendary Takeda clan in 1575. Takeda was ultimately defeated but, as in all Total War battles, victory lies in your hands and by playing one of these three factions you can repeat history... or even rewrite it!
Special armour for your avatar – this complete set of armour will make your General’s avatar stand out on the battlefield and will reward you with the Bad Omen retainer that affects morale to enemy ashigaru (foot soldier) units, giving you a competitive advantage online.
Bank account of XP for your avatar – only the Limited Edition owners will be able to start their General’s avatar at a higher level, with instant access to one upgrade point to spend on special skills or traits.

It is the middle of the 16th century in Medieval Japan. The country, once ruled by a unified government, is now split into many warring clans. The player takes on the role of one Daimyo, the clan leader, and will use military engagements, empire-building, honour, economics and diplomacy to achieve the ultimate goal: re-unite Japan under his supreme command and become the new Shogun, the undisputed ruler of Japan. Set during the golden age of Samurai warfare, Shogun 2 brings to life the most turbulent period of Japanese history.

Extremely harsh cold-voting went on here. You could have it for this price from Zavvi a few weeks ago (when I got mine), it went back up shortly after and is now back to £17.85 again. It still beats most prices for the regular edition elsewhere.